Sumobot

vallavan

Hello to my fellow engineers. I'm new here so bear with me. I'm a final year eng student at monash university in malaysia. My question is abt the sumobot. I want to know how do i program in BS2 to find out the distance of an object using the IR LED sensors. Can't figure out. I would appreciate it if someone could answer me. Or do i have to use another sensor, say a ultrasonic sensor. But jes say that i have no time to order for extra sensors. Thank you. Will be waiting for anyone's reply.

allanlane5

There's a very clever technique, worked out a few years ago, and Parallax now publishes it. Sadly, I don't know where they publish it.

Basically, the approach is this. The IR-LED sensors work by detecting reflected IR light, that's blinking at 38 Khz. So you use a "FREQOUT IrLED 38500" to generate that LED signal, then read the output of the IR-Detector to see if it got it.

Well, the clever idea is, if you output DIFFERENT frequencies than 38,500 then the IR-Detector has less sensitivity, so will only detect things CLOSER than if you used 38,500.

So, you can now do some simple experiments to "detune" the output (use other than 38500) and see how close something has to be in order to be detected.

It won't get you a precise measurement, but hopefully it will give you "Close -- Middle -- Far Away".